It can be hard to plan for an event that won't take place for decades.
But when it comes to retirement, tucking money away early will lead to exponential growth in the future.
If you want to save millions by the time you are 40, you'll need to put away a substantial amount of money as soon as you land your first job.
CNBC crunched a range of numbers to give you some options.
Here's how much you will need to start investing every month to reach $2 million — broken down by your target age.
First, let's go over how we got the numbers. The math assumes you are starting with no money in savings, that your investments will earn 4% in annual returns, and that you start saving at 22 and fresh out of college.
Check out this video to dive into the figures.
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Disclosure: NBCUniversal and Comcast Ventures are investors in Acorns.